1. Field of the Invention
The present invention relates to the field of medical equipments, and more particularly to an X-ray CT scanner used for a CT examination and an image creating method.
2. Description of the Related Art
In the technology of a conventional CT scanner, an apparatus having a wide imaging range (a large detector row) has been used. In such an X-ray CT scanner having a wide imaging range, dynamic scan that continuously scans a specific position (which will be referred to as 4D dynamic scan hereinafter) is carried out.
Further, when executing this 4D dynamic scan, it is important to perform the scan in a state where a contrast agent is sufficiently spread in a subject. Furthermore, when creating a necessary image based on this 4D dynamic scan, an operator estimates a time zone that the contrast agent reaches a test region and creates the image at this timing (see, e.g., JP-A 2008-48956 (KOKAI) and JP-A 1995-194588 (KOKAI)).
However, a judgment of estimating a time that the contrast agent reaches is difficult, and hence a created image is visually confirmed and an image in a time zone which is considered to be optimum is again created. Therefore, there is a problem that an amount of image data is enormous and a process from an examination to a diagnosis requires a large time.
Moreover, in an examination based on the 4D dynamic scan, a process from an examination to a diagnosis must be smoothly carried out. Thus, the acquisition of an image in a necessary time zone must be readily or automatically executed, and easily performing post-processing after using such an image is desired.